1. Field of the Invention
This invention relates to a hydraulic compensation device for compensating a positional deviation of a brake pad, more particularly to a hydraulic compensation device, which has an indicating rod for indicating the amount of the positional deviation of the brake pad.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional hydraulic compensation device is shown to comprise a container 1, a piston 2, a push member 3, a cap 4 and an operating knob member 5. The conventional hydraulic compensation device is adapted for compensating a positional deviation of a brake pad (not shown) which is wearable due to its braking action and which, in use, is mounted on and which is controlled by a hydraulic actuator (not shown).
The container 1 is mounted on a brake line 6 and is adapted to receive brake oil 102 to be supplied to the hydraulic actuator via the brake line 6. The container 1 is communicated with the brake line 6 and the hydraulic actuator. The piston 2 is mounted slidably inside the container 1, and has an O-ring 200 provided thereon in order to confine the brake oil 102 with the container 1. The push member 3 is disposed rotatably inside the container 1, and abuts against the piston 2. The push member 3 is movable threadedly to push the piston 2 toward one end portion of the container 1, thereby moving the hydraulic actuator and adjusting the position of the brake pad. The cap 4 has a tubular wall 401 having an externally threaded surface 403 that engages an internally threaded surface 101 of the container 1 outwardly of the push member 3, and an internally threaded surface 402 that engages an externally threaded surface 301 of the push member 3. The operating knob member 5 is mounted rotatably on the cap 4, and has two elongated ribs 504 that extend through the cap 4 and that engage the push member 3. Therefore, the push member 3 can be rotated by the operating knob member 5 to move the piston 2 toward one end portion of the container 1, thereby adjusting the position of the brake pad. However, the user is unable to know the exact extent of wearing of the brake pad during adjustment with the use of the conventional hydraulic compensation device.